receiving data from pc to PIC 16F877A with compiler hi-tech - microcontroller

Question

I try to send the data from pc to the pic microcontroller. I am a beginner in PIC.
I send the data from hyperterminal and the data will display in the led in port B of PIC.
I used 10Mhz clock and the connection in 9600 baudrate.
here my uart.h program:
char UART_Init(const long int baudrate)
{
unsigned int x;
x = (_XTAL_FREQ - baudrate*64)/(baudrate*64);
if(x>255)
{
x = (_XTAL_FREQ - baudrate*16)/(baudrate*16);
BRGH = 1;
}
if(x<256)
{
SPBRG = x;
SYNC = 0;
SPEN = 1;
TRISC7 = 1;
TRISC6 = 1;
CREN = 1;
TXEN = 1;
return 1;
}
return 0;
}
char UART_TX_Empty()
{
return TRMT;
}
char UART_Data_Ready()
{
return RCIF;
}
char UART_Read()
{
while(!RCIF);
return RCREG;
}
void UART_Read_Text(char *Output, unsigned int length)
{
int i;
for(int i=0;i<length;i++)
Output[i] = UART_Read();
}
void UART_Write(char data)
{
while(!TRMT);
TXREG = data;
}
void UART_Write_Text(char *text)
{
int i;
for(i=0;text[i]!='\0';i++)
UART_Write(text[i]);
}
and this is my main program:
#include<htc.h>
#include<pic.h>
#define _XTAL_FREQ 10000000 //Clock Frequency
#include "uart.h"
void main()
{
TRISB = 0x00; //PORTB as Output
UART_Init(9600);
do
{
if(UART_Data_Ready())
PORTB = UART_Read();
__delay_ms(1000);
}while(1);
}
in hyperteminal I send data say 10010010 but the led in port B do not respond, are there any error in my program?

Answer 1

You have several steps: initialize UART, initialize LEDs, communicate over UART and setup your PC's UART. Which components have you successfully written and tested? You say you're a beginner, so what is the smallest functional program you have successfully executed on a PIC? I've been working with microcontrollers for years, but I still schedule about a whole day to get a single LED to turn on because it could be a software problem, a hardware problem, a voltage problem, an oscillator problem, a PCB problem or a compiler problem.
Here are the steps I take for microchip bring up:
Go over the oscillator section, the configuration bits section, the watchdog section and the pinout section (looking for VDD and VSS) in the datasheet. These are some of the hardest parts to get right. (A gotcha about the oscillator: just because you can program a chip, doesn't mean the oscillator is working because the programmer provides it's own clock.)
Write the bare-minimum code to turn on a single LED.
Write the bare-minimum code to make the LED blink (just use a for-loop delay for now, timers come later)
Write UART initialization code and transmit a single character, I use captial U because it's pretty in binary. TXREG = 'U';
Connect the UART to a PC and see if the hyperterminal sees the U. If it doesn't, I connect an oscilscope to the lines to make sure that the PIC is transmitting, that the PC transmits when I type characters and that the timing of the edges matches.
Within the PIC code, have the UART echo characters from the terminal. (TXREG = RXREG;), and then type on the hyperterminal and make sure the characters are echoed back.
One more note:
Do not have the PIC perform the SPBRG calculation. PIC16 are 8-bit processors and 10000000 requires 32-bits to store. There might be hiccups with the integer divison. It might not have a bug in it, but there's no need to have the PIC calculate it each time. Calculate it before-hand and hard-code the value.